Bulletin - United States National Museum - Smithsonian Institution

76 BULLETIN 91, UNITED STATES NATIONAL MUSEUM.
posterior to the suture, which is equal in strength to the spiral cord at
the periphery. The sulcus between the two spiral cords and between
the anterior cord and the periphery of the last whorl are marked by
the continuations of the axial ribs. Sutures strongly channeled.
Periphery of the last whorl rendered decidedly angulated by the
spiral cord. Base rather long, well rounded, narrowly umbilicated.
The entire surface is marked by slender spiral striations. Aperture
broadly oval; outer lip moderately thick; inner lip somewhat curved
and slightly revolute ; columella provided with an oblique fold at its
insertion; parietal wall glazed with a thick callus.
The type, Cat. No. 250374, U.S.N.M., comes from Port Alfred
(Coll. No. 1247). It has eight postnuclear whorls, and measures:
Length, 5 mm.; diameter, 1.8 mm. Cat. No. 250361, U.S.N.M., contains
the nucleus of a young specimen from the same place (Coll. No.
1234).
TURBONILLA (STRIOTURBONILLA) SECURA, new name.
Plate 17, fig. 7.
Turbonilla dbeliseus Gould, Proc. Bost. Soc. Nat, Hist,, vol. 7, p. 406, 1861. Not
Chemnitzia obcliscus C. B. Adams, Contr. Conch., pp. 72-73, 1850. (Also a
StrioturboniUa).
Shell quite large, broadly conic, bluish-white. Nuclear whorls one
and three-fourths, rather large, forming a well-rounded, depressed,
helicoid spire, the axis of which is at right angles to that of the succeeding
turns. Postnuclear whorls moderately rounded, narrowly
shouldered at the summit, marked by rather strong, low, rounded,
decidedly pro tractive, axial ribs, of which 16 occur upon the first to
third, 18 upon the fourth to sixth, 20 upon the seventh, 24 upon the
eighth and ninth, 26 upon the tenth and penultimate whorl. The
spaces between the axial ribs are narrower than the ribs, and not
very strongly impressed. Suture slightly channeled. Periphery of
the last whorl well rounded ; base short, well rounded. Entire surface
of base and spire marked by rather strong incremental lines and very
fine, closely spaced, wavy, spiral striations. Aperture subquadrate,
posterior angle obtuse; outer lip thin, showing the external sculpture
within; inner lip decidedly oblique and slightly revolute; parietal
wall glazed with a thin callus.
Cat. No. 165, U.S.N.M., contains Gould's type, collected by William
Stimpson on the North Pacific Exploring Expedition, at Simons Bay,
Cape of Good Hope. It has 12 postnuclear whorls and measures:
Length, 11.1 mm.; diameter, 3 mm. Cat. No. 186843, U.S.N.M.,
three specimens from Port Alfred (Coll. No. 210).
TURBONILLA (STRIOTURBONILLA) LAEVOCOSTATA Sowerby.
Cat. No. 186845, U.S.N.M., contains sLx specimens of this species
from Port Alfred (Coll. No. 212).